Historical tests of the absolute completeness of the fossil record of tetrapods

Paleobiology ◽  
1990 ◽  
Vol 16 (3) ◽  
pp. 322-335 ◽  
Author(s):  
W. Desmond Maxwell ◽  
Michael J. Benton
Keyword(s):  
Fossil Record ◽  
Upper Devonian ◽  
Data Bases ◽  
Diversity Pattern ◽  
The Absolute

Six compilations of fossil tetrapod families, spanning 100 years, each contain a broadly similar diversity pattern since the Upper Devonian. Comparison of four recent data bases, one of which is derived from a strict cladistic treatment, reveals widespread taxonomic and stratigraphic inaccuracies in three earlier data bases. Improvement of our interpretation of the tetrapod fossil record will come through continued taxonomic and stratigraphic revision as well as discovery of new fossils.

An enigmatic blastozoan echinoderm fauna from central kentucky

2009 ◽  
Vol 83 (5) ◽  
pp. 739-749 ◽  
Author(s):  
Colin D. Sumrall ◽  
Carlton E. Brett ◽  
Troy A. Dexter ◽  
Alexander Bartholomew
Keyword(s):  
North America ◽  
Northwest Territories ◽  
Middle Devonian ◽  
Fossil Record ◽  
Foreland Basin ◽  
Late Ordovician ◽  
Upper Devonian ◽  
Range Extension ◽  
First Report ◽  
Appalachian Foreland

A series of small road cuts of lower Boyle Formation (Middle Devonian: Givetian) near Waco, Kentucky, has produced numerous specimens of three blastozoan clades, including both “anachronistic” diploporan and rhombiferan “cystoids” and relatively advanced Granatocrinid blastoids. This unusual assemblage occurs within a basal grainstone unit of the Boyle Limestone, apparently recording a local shoal deposit. Diploporans, the most abundant articulated echinoderms, are represented by a new protocrinitid species, Tristomiocystis globosus n. gen. and sp. Glyptocystitoid rhombiferans are represented by isolated thecal plates assignable to Callocystitidae. Three species of blastoids, all previously undescribed, include numerous thecae of the schizoblastid Hydroblastus hendyi n. gen. and sp., the rare nucleocrinid Nucleocrinus bosei n. sp., and an enigmatic troosticrinid radial. The blastoid Nucleocrinus is typical for the age; however, the callocystitid, schizoblastid, and protocrinitid are not. Hydroblastus is the oldest known schizoblastid. Middle and Upper Devonian callocystitids have been previously reported only from Iowa and Michigan USA with unpublished reports from Missouri USA and the Northwest Territories, Canada. This occurrence is thus the first report of a Middle Devonian rhombiferan from the Appalachian foreland basin. Tristomiocystis is the first known protocrinitid in North America and the only protocrinitid younger than Late Ordovician. This occurrence thus represents a range extension of nearly 50 million years for protocrinids. This extraordinary sample of echinoderms in a Middle Devonian limestone from a well-studied area of North America highlights the incompleteness of the known fossil record, at least in fragile organisms such as echinoderms.

Ten years in the library: new data confirm paleontological patterns

Paleobiology ◽  
1993 ◽  
Vol 19 (1) ◽  
pp. 43-51 ◽  
Author(s):  
J. John Sepkoski
Keyword(s):  
Fossil Record ◽  
Goodness Of Fit ◽  
Marine Animal ◽  
Low Resolution ◽  
Data Bases ◽  
Marine Fauna ◽  
Paleontological Data ◽  
Principal Difference ◽  
Library Research

A comparison is made between compilations of times of origination and extinction of fossil marine animal families published in 1982 and 1992. As a result of ten years of library research, half of the information in the compendia has changed: families have been added and deleted, low-resolution stratigraphic data have been improved, and intervals of origination and extinction have been altered. Despite these changes, apparent macroevolutionary patterns for the entire marine fauna have remained constant. Diversity curves compiled from the two data bases are very similar, with a goodness-of-fit of 99%; the principal difference is that the 1992 curve averages 13% higher than the older curve. Both numbers and percentages of origination and extinction also match well, with fits ranging from 83% to 95%. All major events of radiation and extinction are identical. Therefore, errors in large paleontological data bases and arbitrariness of included taxa are not necessarily impediments to the analysis of pattern in the fossil record, so long as the data are sufficiently numerous.

scholarly journals Crustacean biodiversity through the marine fossil record

2000 ◽  
Vol 69 (4) ◽  
pp. 213-222 ◽  
Author(s):  
J. John Sepkoski
Keyword(s):  
Fossil Record ◽  
Major Group ◽  
Mass Extinctions ◽  
Data Bases ◽  
Extinction Rates ◽  
Marine Crustaceans ◽  
History Of ◽  
Fossil Preservation ◽  
Fossil Records ◽  
High Diversity

Approximately 2,600 genera of marine crustaceans have been recognized in the fossil record, and crustaceans constitute the major component of marine arthropod diversity from the mid- Paleozoic to the Recent. Despite problems of sporadic fossil preservation and/or taxonomic ambiguity, some general statements can be made about the history of crustacean biodiversity, based on global taxonomic data bases. Ostracodes were the first major group to radiate, attaining high diversity during the Ordovician Period with other members of the Paleozoic evolutionary fauna; rates of extinction and responses to mass extinctions were also similar to those of groups within the Paleozoic fauna. Malacostracans and barnacles (cirripedes), the two other crustacean groups with important fossil records, had minor diversity throughout the Paleozoic Era. Both groups experienced diversification from the mid-Mesozoic to Recent with lower extinction rates, as characteristic members of the Modern evolutionary fauna.

The Silurian-Devonian fossil record of the Myriapoda

1985 ◽  
Vol 309 (1138) ◽  
pp. 227-237 ◽  
Keyword(s):  
New York ◽  
Fossil Record ◽  
Discrete Group ◽  
Lower Devonian ◽  
New York State ◽  
Upper Devonian ◽  
York State ◽  
Red Sandstone ◽  
Terrestrial Invertebrates ◽  
Terrestrial Invertebrate

The oldest recorded terrestrial invertebrates are various small Diplopods (millepedes) from the Lower Old Red Sandstone of Britain which were probably preserved preferentially due to their robust calcified exoskeleton. While the myriapod affinities and terrestrial habits of the earliest, pre-Prídolí, claims are highly questionable, true diplopods are known from the latest Silurian (Stonehaven Group) and Lower Devonian of Scotland. In addition, a variety of enigmatic myriapod-like arthropods occur sporadically in the late Silurian-Lower Devonian freshwater facies of the M idland Valley of Scotland and Welsh Borderlands. Among these, the kampecarids ss. constitute a discrete group of short-bodied, diplopodous uniramian arthropods, possibly with myriapod affinities and aquatic habits. In contrast to the diversity of chelicerate groups represented in the later terrestrial invertebrate faunas of Rhynie, Aiken and Gilboa, the Middle to Upper Devonian fossil record of the Myriapoda is very sparse. While true diplopods are notably absent, a variety of fragmentary chilopods (centipedes) are now known from the Gilboa Fauna (Givetian) of New York State.

Are modern chemosynthesis-based communities a ‘glimpse of antiquity’? The changing fate of bivalves and brachiopods at ancient methane seeps as recorded in the Middle Palaeozoic of Morocco

2020 ◽  
Author(s):  
Michał Jakubowicz ◽  
Krzysztof Hryniewicz
Keyword(s):  
Middle Devonian ◽  
Fossil Record ◽  
Hydrothermal Vents ◽  
Upper Devonian ◽  
Early Evolution ◽  
Methane Seeps ◽  
The Past ◽  
Early Mesozoic ◽  
Morphological Adaptations ◽  
Chemosynthetic Ecosystems

<p>Despite much scientific effort aimed over the past three decades to better constrain the fossil record of chemosynthesis-based communities, our understanding of their early evolution remains fragmentary. Until recently, a dominant perception was that, unlike the Cenozoic, bivalve-dominated chemosynthetic ecosystems, the Paleozoic to mid-Mesozoic methane seeps and hydrothermal vents were dominated by brachiopods. Similarly, the pattern of brachiopod vs. bivalve predominance at seeps and vents over the Phanerozoic was believed to have crudely followed that observed in normal-marine benthic shelly assemblages. Recent discoveries from the Middle Palaeozoic of Morocco have questioned this simple perception, documenting the presence of late Silurian and Middle Devonian seeps dominated by mass accumulations of large, semi-infaunal, modiomorphid bivalves (Hryniewicz et al., 2017; Jakubowicz et al., 2017). While representing a lineage unrelated to modern seep-obligate bivalve taxa, the mid-Palaeozoic seep bivalves developed a set of morphological adaptations strikingly similar to those of their modern ecological counterparts, and formed analogous, densely-packed, nearly monospecific assemblages, both suggesting their chemosymbiotic lifestyle. The new documentation of Palaeozoic establishment of the bivalve-dominated seep communities provides a fresh look at the concept of modern chemosynthetic ecosystems as a 'glimpse of antiquity', showing that although it is largely not true taxonomically, it clearly is in terms of recurring morphological themes. At the same time, this refined Palaeozoic record makes the factors responsible for the apparent scarcity of seep-related bivalves during the upper Devonian to early Mesozoic, a period of the remarkable success of brachiopod-dominated seep assemblages, ever more enigmatic.</p>

scholarly journals The unique fossil assemblage from the Lode Quarry (Upper Devonian, Latvia)

Fossil Record ◽  
2001 ◽  
Vol 4 (1) ◽  
pp. 101-119 ◽  
Author(s):  
I. Upeniece
Keyword(s):  
Fossil Record ◽  
Juvenile Fish ◽  
Upper Devonian ◽  
Ontogenetic Change ◽  
Fossil Assemblage ◽  
Unique Data ◽  
Parasitic Association ◽  
Main Devonian Field ◽  
Lower Frasnian ◽  
Parasitic Platyhelminth

The unique fossil fauna from the Lode clay quarry, lower Frasnian, Latvia, includes a diverse ichthyofauna of at least 15 taxa of agnathans and gnathostomes, representing most of the major taxa of Devonian vertebrates. Six new fish taxa (five species and one genus) were discovered during the last ten years. Exceptionally well-preserved juvenile fishes (<i>Asterolepis ornata, Lodeacanthus gaujicus</i>) provide unique data on ontogenetic change. Diverse arthropods are recorded. Parasitic platyhelminth remains in juvenile fish bodies is their first discovery in the fossil record, and represents the oldest parasitic association ever found. A complete faunal and floral list for the Lode quarry is presented, with a detailed biostratigraphic section. Comparison of vertebrata taxa from the Gauja Regional Stage with similar of the Main Devonian Field, Scotland, Timan, Canada, and Germany is reviewed. <br><br> Die einzigartige Lebensgemeinschaft von Lode repräsentiert eine diverse Fischfauna nahezu aller Hauptwirbeltiertaxa, die im Devon lebten. Sechs neue Fischtaxa (5 Arten und 1 Gattung) wurden in den letzten zehn Jahren in den Unter-Frasnium-Schichten der Ziegeleigrube von Lode in Lettland entdeckt. Insgesamt sind 15 identifizierte und unbestimmte Fisch- und Agnathen-Arten von dort bekannt. Besondere Beachtung wurde den außergewöhnlich gut erhaltenen Jugendformen von <i>Asterolepis ornata</i> und <i>Lodeacanthus gaujicus</i> und verschiedenen Invertebraten (Crustacea, Merostomata) gespendet, die in einer einzigen Linse fein verteilten Tones gefunden wurden. Reste parasitischer Platyhelminthen, die in Jungfischen auftreten, wurden hier zum ersten Mal als Fossilien entdeckt; sie repräsentieren die älteste bisher gefundene parasitische Gemeinschaft. Eine Liste der organischen Reste aus den Schichten der Ziegeleigrube Lode wird präsentiert. Ein detailliertes biostratigraphisches Profil wird beschrieben. Die Fischfaunen aus der Gauja Regional-Stufe werden mit denen vom Hauptdevonfeld Russlands, von Schottland, dem Timan, Kanadas und Deutschlands verglichen. <br.><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20010040108" target="_blank">10.1002/mmng.20010040108</a>

Completeness of the mammalian fossil record in the Iberian Neogene

Paleobiology ◽  
2001 ◽  
Vol 27 (1) ◽  
pp. 79-83 ◽  
Author(s):  
David M. Alba ◽  
Jordi Agustí ◽  
Salvador Moyà-Solà
Keyword(s):  
Iberian Peninsula ◽  
Fossil Record ◽  
Marine Invertebrates ◽  
Marine Invertebrate ◽  
Specific Level ◽  
The Absolute ◽  
Stratigraphic Ranges ◽  
Mammalian Fossil ◽  
Favorable Conditions ◽  
Analytical Tools

We infer the absolute completeness of the mammalian fossil record of the Iberian Neogene, from a compiled database of preserved stratigraphic ranges for both species and genera and by means of the analytical tools developed by Foote and Raup (1996). We conclude that the mammalian fossil record from the Neogene of the Iberian Peninsula is very complete (more than 75% at the specific level, and more than 90% at the generic one), being a good indicator of how complete the record of terrestrial organisms can be at least under certain favorable conditions. Comparison with previously published results for well-known marine invertebrates indicates that the continental Iberian Neogene record is not significantly less complete, thus raising doubts about the importance of more episodic deposition in continental environments. It remains to be seen if continental faunas in general are as complete as the marine invertebrate record.

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

A Quantitative Ultrastructural Study of Peripheral Blood Lymphocytes Containing Parallel Tubular Arrays in Epstein-Barr Virus and Cytomegalo-Virus Mononucleosis

1981 ◽  
Vol 39 ◽  
pp. 454-455
Author(s):  
C. M. Payne ◽  
P. M. Tennican
Keyword(s):  
Peripheral Blood ◽  
Lymphocyte Count ◽  
Epstein Barr Virus ◽  
Absolute Lymphocyte Count ◽  
Peripheral Blood Lymphocytes ◽  
Clinical State ◽  
Barr Virus ◽  
The Absolute ◽  
Epstein Barr ◽  
Tubular Arrays

In the normal peripheral circulation there exists a sub-population of lymphocytes which is ultrastructurally distinct. This lymphocyte is identified under the electron microscope by the presence of cytoplasmic microtubular-like inclusions called parallel tubular arrays (PTA) (Figure 1), and contains Fc-receptors for cytophilic antibody. In this study, lymphocytes containing PTA (PTA-lymphocytes) were quantitated from serial peripheral blood specimens obtained from two patients with Epstein -Barr Virus mononucleosis and two patients with cytomegalovirus mononucleosis. This data was then correlated with the clinical state of the patient.It was determined that both the percentage and absolute number of PTA- lymphocytes was highest during the acute phase of the illness. In follow-up specimens, three of the four patients' absolute lymphocyte count fell to within normal limits before the absolute PTA-lymphocyte count.In one patient who was followed for almost a year, the absolute PTA- lymphocyte count was consistently elevated (Figure 2). The estimation of absolute PTA-lymphocyte counts was determined to be valid after a morphometric analysis of the cellular areas occupied by PTA during the acute and convalescent phases of the disease revealed no statistical differences.

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